Modular robotic vehicle

ABSTRACT

A robotic vehicle may include a power module and a working module. The power module may include control circuitry configured to execute stored instructions to direct operation of the robotic vehicle on a defined area, and a drive motor for propelling the robotic vehicle responsive to control by the control circuitry. The working module may be configured to perform a function with respect to the defined area responsive to being propelled by the power module. The working module may be one of a plurality of interchangeable working modules that are attachable to the power module. At least one of the interchangeable working modules may have a different function than the working module.

TECHNICAL FIELD

Example embodiments generally relate to robotic vehicles and, moreparticularly, relate to a robotic vehicle that has a modularconstruction.

BACKGROUND

Yard maintenance tasks are commonly performed using various tools and/ormachines that are configured for the performance of correspondingspecific tasks. Certain tasks, like grass cutting, are typicallyperformed by lawn mowers. Lawn mowers themselves may have many differentconfigurations to support the needs and budgets of consumers.Walk-behind lawn mowers are typically compact, have comparatively smallengines and are relatively inexpensive. Meanwhile, at the other end ofthe spectrum, riding lawn mowers, such as lawn tractors, can be quitelarge. More recently, robotic mowers and/or remote controlled mowershave also become options for consumers to consider.

Lawn mowers are typically capable of transiting over even and uneventerrain to execute yard maintenance activities relating to mowing.However, most lawn mowers are repeatedly exposed to the same operatingenvironments over the course of their lifetimes. For example, a lawnmower may operate to cut a single yard over its entire life, or mayoperate to cut a relatively fixed series of yards or parcels if it isused for commercial purposes. Given that computing devices are becomingmore ubiquitous, it is to be expected that they may be employed toassist in operation of lawn mowers. As such, many additionalfunctionalities may be provided or supported by the employment ofcomputing devices on lawn mowers.

A robotic mower is one example of a device that employ an onboardcomputing device to enable its function. Moreover, such a mower iscapable of autonomous or self-guided operation under the control of sucha computing device. To control its operation, a robotic mower may employa plurality of sensors to detect various boundaries and/or objects or todetect events such as a collision with an object, or detect when themower has been lifted or tipped over. Detecting these events may beuseful in controlling the application of drive and/or cutting power, orproviding other control functions.

A typical robotic mower fits all of its electronics and hardware onto asingle chassis. Accordingly, such a mower is relatively limited withrespect to its ability to be adapted to other uses, or to be adaptedwith respect to its form relative to its intended use.

BRIEF SUMMARY OF SOME EXAMPLES

Some example embodiments may therefore provide a robotic device having amodular construction. By employing a modular construction, the devicemay be very adaptable by simply switching out various modules that areusable in connection with the device. Such a modular construction mayalso enable other benefits to be realized such as improvements relatedto control of cutting height on mower embodiments, improvement withrespect to care and cleaning, improvements with respect to maintainingground coverage over difficult terrain, and/or the like.

In an example embodiment, a robotic vehicle is provided. The roboticvehicle may include a power module and a working module. The powermodule may include control circuitry configured to execute storedinstructions to direct operation of the robotic vehicle on a definedarea, and a drive motor for propelling the robotic vehicle responsive tocontrol by the control circuitry. The working module may be configuredto perform a function with respect to the defined area responsive tobeing propelled by the power module. The working module may be one of aplurality of interchangeable working modules that are attachable to thepower module. At least one of the interchangeable working modules mayhave a different function than the working module.

In another example embodiment, a robotic vehicle is provided that mayinclude a power module and a working module. The power module mayinclude control circuitry configured to execute stored instructions todirect operation of the robotic vehicle on a defined area, and a drivemotor for propelling the robotic vehicle responsive to control by thecontrol circuitry. The working module may have a frame and be configuredto perform a function with respect to the defined area responsive tobeing propelled by the power module. The power module may include auniversal frame support extending from a front portion of the powermodule to rotatably engage a portion of the frame of the working module.

In yet another example embodiment, a robotic vehicle is provided thatmay include a power module and a cutting deck. The power module mayinclude control circuitry configured to execute stored instructions todirect operation of the robotic vehicle on a defined area, and a drivemotor for propelling the robotic vehicle responsive to control by thecontrol circuitry. The cutting deck may include a frame that is operablycoupled to a cutter support beam supporting a plurality of cutting discsconfigured to perform a cutting function with respect to the definedarea responsive to being propelled by the power module. The cutting deckmay be releasably and pivotally attached to a forward portion of thepower module.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, which are not necessarily drawn toscale, and wherein:

FIG. 1 illustrates an example operating environment for a robotic mower;

FIG. 2A illustrates a schematic view of a lower chassis and variouscomponents of the robotic mower according to an example embodiment;

FIG. 2B illustrates a schematic view of an upper chassis and variousother components of the robotic mower according to an exampleembodiment;

FIG. 3 illustrates a perspective view of some components of a cuttingdeck that is one example of a working module according to an exampleembodiment;

FIG. 4 illustrates a perspective view of the cutting deck tipped up forcleaning according to an example embodiment;

FIG. 5 illustrates a perspective view of the cutting deck with the coverremoved to expose some of the components of the cutting deck accordingto an example embodiment; and

FIG. 6 illustrates a perspective view of a portion of the cutting deckto illustrate how height adjustments may be made according to oneexample embodiment.

DETAILED DESCRIPTION

Some example embodiments now will be described more fully hereinafterwith reference to the accompanying drawings, in which some, but not allexample embodiments are shown. Indeed, the examples described andpictured herein should not be construed as being limiting as to thescope, applicability or configuration of the present disclosure. Rather,these example embodiments are provided so that this disclosure willsatisfy applicable legal requirements. Like reference numerals refer tolike elements throughout. Furthermore, as used herein, the term “or” isto be interpreted as a logical operator that results in true wheneverone or more of its operands are true. As used herein, operable couplingshould be understood to relate to direct or indirect connection that, ineither case, enables functional interconnection of components that areoperably coupled to each other.

Robotic vehicles such as robotic mowers, robotic watering devices,robotic brush cutters, robotic snow movers, and/or the like, typicallyoperate in an area that is defined by some technical implementation bywhich to define boundaries such as, for example, a guide wire thatbounds the area to be worked. The robotic vehicle then roams within thebounded area to ensure that the entire area is mowed, watered, orotherwise worked, but the robotic vehicle does not go outside of thebounded area.

FIG. 1 illustrates an example operating environment for a roboticvehicle 10 that may employ a system bounded by such a guide wire.Although the robotic vehicle 10 is perhaps most commonly seen embodiedas a robotic mower, it should be appreciated that a robotic mower ismerely an example of a robotic vehicle that may employ an exampleembodiment. The robotic vehicle 10 may operate to work on a parcel 20(i.e., a land lot), the boundaries of which may be defined using one ormore physical boundaries (e.g., a fence, wall, curb and/or the like), aguide wire 30 or combinations thereof. The guide wire 30 may emitelectrical signals that are detectable by the robotic vehicle 10 toinform the robotic vehicle 10 when a boundary of the parcel 20 has beenreached. The robotic vehicle 10 may be controlled, at least in part, viacontrol circuitry 12 located onboard. The control circuitry 12 mayinclude, among other things, the ability to detect the guide wire 30 toredirect the robotic vehicle 10 to other areas within the parcel 20.

In an example embodiment, the robotic vehicle 10 may be battery poweredvia one or more rechargeable batteries. Accordingly, the robotic vehicle10 may be configured to return to a charge station 40 that may belocated at some position on the parcel 20 in order to recharge thebatteries. The batteries may power a drive system and a blade controlsystem of the robotic vehicle 10. However, the control circuitry 12 ofthe robotic vehicle 10 may selectively control the application of poweror other control signals to the drive system and/or the blade controlsystem to direct the operation of the drive system and/or blade controlsystem. Accordingly, movement of the robotic vehicle 10 over the parcel20 may be controlled by the control circuitry in a manner that enablesthe robotic vehicle 10 to systematically traverse the parcel 20 whileoperating a cutting blade to cut the grass on the work area of theparcel 20.

In some embodiments, the control circuitry 12 of the robotic vehicle 10may be configured to communicate with an electronic device 42 (e.g., acomputer, mobile telephone, PDA, smart phone, and/or the like) of aremote operator 44 via a wireless communication network 46. However, thewireless network 46 and other remote devices may not be employed in someembodiments, as described below. If employed, the wireless network 46may be a data network, such as a local area network (LAN), ametropolitan area network (MAN), a wide area network (WAN) (e.g., theInternet), and/or the like, which may couple the robotic vehicle 10 todevices such as processing elements (e.g., personal computers, servercomputers or the like) or databases. In some cases, the wireless network46 may be a peer-to-peer (P2P) network or a proprietary network.Communication between the wireless network 46 and the devices ordatabases (e.g., servers, electronic device 42, control circuitry 12)may be accomplished by either wireline or wireless communicationmechanisms and corresponding protocols.

FIG. 2, which includes FIGS. 2A and 2B, illustrates some of the generalparts that may be employed in connection with an example of the roboticvehicle 10. However, it should be appreciated that example embodimentsmay be employed on numerous other vehicles that may employ differentdesigns. FIG. 2A illustrates a schematic view of a lower chassis andvarious components of the robotic mower according to an exampleembodiment and FIG. 2B illustrates a perspective view of the roboticmower according to an example embodiment. It should be appreciated thatthe robotic vehicle 10 may take different forms or shapes, and mayinclude different components in some embodiments. Moreover, it should beappreciated that the arrangement of components shown in FIG. 2A could bechanged in alternative embodiments, and the components are not drawn toscale.

Referring to FIGS. 1 and 2, the robotic vehicle 10 may include a workingmodule 50 and a power module 60 (or carrier unit). The working module 50may be any of a number of working attachments that may be affixed to thepower module 60 to perform a particular function. For example, in somecases, the working module 50 may include a cutting deck, a snow throwingattachment, a brush cutting attachment, a sweeping attachment and/or thelike. In an example embodiment, the working module 50 may be fixed tothe power module 60 at the factory or otherwise before shipment to orpurchase by the user. However, in other cases, the working module 50 maybe attached by the user. Moreover, in some cases, the working module 50may be relatively easy to remove and replace with other interchangeableworking modules. For example, an entirely different function may beenabled by providing a different working module 50. Alternatively oradditionally, the size of the working module may be increased ordecreased and/or different modules with corresponding accessories may beprovided for attachment at the user's option.

The power module 60 may include a lower chassis 62 or other chassiscomponent which may form a frame or base structure upon which othercomponents may be provided. In an example embodiment, the lower chassis62 may support one or more batteries in a battery pack 64. The lowerchassis 62 may also support a drive motor 66 that may be configured toturn wheels 68 based on control signals provided by the controlcircuitry 12 using power from the battery pack 64. As such, the lowerchassis 62 may also form a support structure from which the wheels 68may be supported. In some embodiments, the wheels 68 may be configuredto operate either in a forward or backward direction, but may otherwisenot be steerable. However, in some alternative embodiments, the wheels68 may also be enabled to contribute to steering, or an additional setof wheels for providing steering inputs may be provided.

In some embodiments, the battery pack 64 may also power a work motor 70that may be supported on the power module 60. However, in otherexamples, the battery pack 64 may power one or more individual workmotors that may be disposed at the working module 50 to power componentsthereof. In an example embodiment, the power module 60 may also includea user interface 72 and one or more sensors 74 that may form part of asensor network, or may stand alone to sense any of various parametersassociated with the robotic vehicle 10. The user interface 72 may beemployed to interface with the control circuitry 12 for controllingoperations of the robotic vehicle 10.

In an example embodiment, each of the power module 60 and the workingmodule 50 may include a housing or cover (see covers 76 and 78,respectively) to provide an aesthetically pleasing exterior, contain orrepel materials, and/or protect components from impact or naturalelements. In one example embodiment, the user interface 72 may bedisposed on the cover 76 of the power module 60.

In an example embodiment, the one or more sensors 74 may be used todetect the guide wire 20 and/or objects that may form part of theboundary of the parcel. The sensors 74 may also detect objects that maybe encountered during operation of the robotic vehicle 10 within theboundaries of the parcel 20. These objects may be fixed or temporary(e.g., movable) objects. In some cases, the sensors 74 may include afront sensor and a rear sensor. However, it should be appreciated thatany number of sensors may be employed and they may be disposed at anydesirable location on the robotic vehicle 10. The sensors 74 may, insome cases, include sensors related to positional determination (e.g., aGPS receiver, an accelerometer, a camera, a radar transmitter/detector,an ultrasonic sensor, a laser scanner and/or the like). Thus, forexample, positional determinations may be made using GPS, inertialnavigation, optical flow, radio navigation, visual location (e.g.,VSLAM) and/or other positioning techniques or combinations thereof.Accordingly, the sensors 74 may be used, at least in part, fordetermining the location of the robotic vehicle 10 relative toboundaries or other points of interest (e.g., a starting point, theguide wire or other key features) of the parcel 20, or determining aposition history or track of the robotic vehicle 10 over time. In otherexamples, the sensors 74 may additionally or alternatively detectcollisions, lifting, tipping or other events related to operation of therobotic vehicle 10.

In some embodiments, the sensors 74 of the sensor network of the roboticvehicle 10, and all other electrical components of the robotic vehicle10 may be in communication with the control circuitry 12 via a singlecommunication bus. Thus, for example, bus-based decentralizedcommunication may be provided in order to enable scaling of cuttingmotors, sensors and/or the like. In an example embodiment, the controlcircuitry 12 may be housed in an electronics box of a standard size sothat additional scaling may be supported to add or remove circuitboards, chips or modules as desired. The battery pack 64 may also behoused in a standard sized or modular battery compartment to allowscaling of the size of the battery pack 64 as appropriate for theequipment being powered thereby. The drive motor 66, work motor 70,mainboard, sensors and other components of the power module 60 maytherefore also be modular and/or replaceable to enable the user toexchange, replace, add or otherwise provide functional units for therobotic vehicle 10 to expand or contract its capabilities as desired. Insome cases, the modular nature of the power module 60 may support theaddition of modules required or desired for operation with particularwork modules 50 that may be selected for operation with the roboticvehicle 10. However, in other examples, a single configuration of thepower module 60 may support a number of different work modules 50.

Accordingly, in an example embodiment, an autonomous or self-guidedrobotic vehicle may be provided that includes a power module and aworking module. The working module may be any one of a number ofinterchangeable different functional attachments that can be attached toa single power module. The different functional attachments may eachhave different purposes, or they may have the same purpose, butdifferent mechanisms for carrying out such purpose. Meanwhile, in somecases, the power module may be interchangeably arranged with any of theworking module embodiments with minimal or no use of tools for makingconfiguration changes. However, in some embodiments, the power modulemay need some minor configuration changes to support certain workingmodules. Meanwhile, modular modifications to the power, controlcircuitry, sensors, or other accessories of the power module may also bepossible when desired.

The separation of the power module 60 and the working module 50 may beuseful for enabling the type of interchangeability described above.However, such separation may also have other benefits. For example,grass waste and other debris that a working module 50 may generate canbe very aggressive relative to deteriorating or corroding plastic,rubber and even metals. Thus, units that combine components of a workingmodule and power module into a single body may require relativelycomplex and expensive design features (e.g., seals, bellows, gaskets,etc.) to attempt to keep critical parts separated from debris. Bydividing the power module 60 from the working module 50 (i.e., makingthem completely separable from each other) according to an exampleembodiment, it may be possible to more economically and effectivelyseparate sensitive parts from debris that could harm them. It may alsobe possible to undertake more aggressive cleaning of working module 50parts without worrying about risk to the more sensitive parts (e.g.,electronics and other sensitive parts) of the power module 60.

In order to enable the power module 60 to support connections tonumerous different variations of the working module 50, the power module60 may be provided with a structural member to which any of a number ofdifferent working accessories or attachments forming examples of theworking module 50 may be attached. FIGS. 3 and 4 illustrate an exampleof such a structural member in the form of a universal frame support100. The universal frame support 100 may extend from a front portion ofthe power module 60 to engage the working module 50, regardless of thespecific embodiment of the working module 50 that is employed (e.g., amower attachment, a snow thrower attachment, a watering attachment,etc.). In some embodiments, the universal frame support 100 may be anextension of the chassis or frame of the power module 60. However, it ispossible for the universal frame support 100 to be a separate componentthat is attached to the frame or chassis of the power module 60.

FIG. 3 illustrates a perspective view of some components of a cuttingdeck 110 that is one example of the working module 50. FIG. 4illustrates a perspective view of the cutting deck 110 tipped up forcleaning or service according to an example embodiment. As shown inFIGS. 3 and 4, the universal support frame 100 may be a substantiallyrectangular shaped structure extending forward of the power module 60.The universal support frame 100 may be formed of metallic or rigidplastic or composite materials formed into bars, rods or other rigidstructures adapted to supporting a load. The universal support frame 100may extend substantially parallel to the ground or other surface overwhich the power unit 60 transits. In this example, the universal supportframe 100 may extend over at least a portion of the working module 50such that the working module 50 may be attached to the universal supportframe 100 at a top portion of the working module 50.

In the example of FIGS. 3 and 4, in which the working module 50 isembodied as the cutting deck 110, the cutting deck 110 may be providedwith a cover 112 and a main frame 114. The cover 112 may enclose cuttingcomponents and the structures to which the cutting components mount.Thus, for example, the cover 112 may enclose the frame 114. However, insome embodiments, the frame 114 may be integrally formed into the cover112. The frame 114 may support components of the cutting deck 110 and,in some embodiments, the frame 114 may support sensors including, forexample, collision and/or lift sensors.

In an example embodiment, a front end of the universal support frame 100may include an attachment joint 120 that is rotatably attachable to thecutting deck 110. In some cases, the attachment joint 120 may beconnected to the cover 112. However, in some embodiments, the attachmentjoint 120 may be operably coupled to the frame 114 via an opening formedin the cover 112. The point of attachment between the attachment joint120 and the cutting deck 110 may be proximate to a front portion of thecover 112. In some cases, the attachment joint 120 may be the only pointat which the universal support frame 100 is coupled to the cover 112 orthe frame 114. However, in some embodiments, a back portion of the cover112 or frame 114 may include a releasable coupling 122 that may engage aportion of the universal support frame 100. The operator may be enabledto release the releasable coupling 122 and pivot the cutting deck 110about the attachment joint 120 in order to expose the underside of thecutting deck 110 without the use of tools. The cutting deck 110 may thenbe cleaned or serviced relatively easily and without requiring theentire robotic vehicle 10 to be tipped over or on its side (or requiringtools or complex mechanical manipulation).

FIGS. 5 and 6 show some of the components of the cutting deck 110 of anexample embodiment in greater detail. In this regard, FIG. 5 illustratesa perspective view of the cutting deck 110 with the cover 112 removed toexpose some of the components of the cutting deck. FIG. 6 illustrates aperspective view of a portion of the cutting deck 110 (again with cover112 removed) to illustrate how height adjustments may be made accordingto one example embodiment.

In some embodiments, the frame 114 may be formed of metallic or rigidplastic or composite materials formed into bars, rods or other rigidstructures adapted to supporting the cover 112 and cutting components ofthe cutting deck 110. In an example embodiment, as shown in FIGS. 5 and6, the frame 114 may include a front member 200 that extendssubstantially transversely across the front of the cutting deck 110along a straight line from one side of the cutting deck 110 to theother. The front member 200 may be joined to a first side member 210that extends substantially perpendicularly rearward from one end of thefront member 200 and a second side member 220 that mirrors the firstside member to extend rearward from the other end of the front member200. In some cases, the distal ends of the first and second side members210 and 220 may be joined together by a rear member 230 that may extendsubstantially straight between the first and second side members 210 and220. Although the rear member 230 may be straight in some cases, therear member 230 of FIG. 5 includes angled portions 232 that extendrearward from the distal ends of the first and second side members 210and 220.

In an example embodiment, the attachment joint 120 may be affixed to abar extension 240 that may extend rearward from a middle portion of thefront member 200. The front member 200 may also have a plurality ofground contacting wheels associated therewith. In this regard, forexample, the front member 200 may provide support for a pair of outerwheels 242 and a center wheel 244. The outer wheels 242 mayalternatively be supported by respective ones of the first and secondside members 210 and 220, as shown in FIG. 5. As such, the outer wheels242 may be supported outside the interior region defined by the frame114. Likewise, the center wheel 244 may be supported outside theinterior region defined by the frame 114 from approximately a centerportion of the front member 200. In one example embodiment, as shown inFIG. 5, the center wheel 244 may be supported from the opposite side ofthe front member 200 to the side on which the bar extension 240 issupported. Furthermore, in order to prevent the center wheel 244 frompressing grass down before it can be cut, some embodiments may providethe center wheel 244 at a different height than the two outer wheels 242(i.e., at a higher elevation such as about 15 mm higher in one case). Assuch, for example, when operating on flat ground, the center wheel 244may not contact the ground while the outer wheels 242 are contacting theground. However, when one of the outer wheels 242 encounters a hole orother depression, rather than the cutting deck 110 dropping on one sidesuch that the grass beneath can be scalped by cutting blades/discs ofthe cutting deck 110, the center wheel 244 may begin contacting theground and hold the cutting deck 110 up so that the grass is notscalped. Thus, the center wheel 244 may be useful for dealing withobstacles that may otherwise cause the cutting deck 110 to hang up.

In an example embodiment, a plurality of cutting discs 250 (or otheroperational tools) may be provided such that each cutting disc 250 isassociated with a corresponding cutting motor 252 to form a plurality ofcutters 254. The cutting motors 252 may receive power from the batterypack 64 of the power module 60. Each of the cutters 254 may be supportedfrom a single cutter support beam 260. The cutter support beam 260 maybe a single unitary bar from which the cutters 254 are suspended.However, it should be appreciated that the cutter support beam 260 couldalternatively be made of multiple pieces in some embodiments. Each ofthe cutters 254 may be suspended from the cutter support beam 260 at thesame height. Thus, at least when passing over flat ground, the cuttingdiscs 250 may each cut to relatively the same height. However, in someembodiments, the heights of each of the cutters 254 may be adjustable.Thus, for example, the operator may be enabled to tip the cutting deck110 as shown in FIG. 4, and then adjust the heights of one or more ofthe cutters 254 relative to the cutter support beam 260.

In order to ensure that there is overlap of the parallel cutting swathsdefined by each of the cutting discs 250 (and therefore an even lookingcut) as the robotic vehicle 10 moves over the ground, it may beadvantageous to offset the cutters 254 along the direction of motion ofthe robotic vehicle 10 as one moves from one side of the cutting deck110 to the other. Accordingly, the cutters 254 may be placed closer toeach other as they extend transversely across the cutting deck 110 fromone side to the other. The parallel swaths may therefore overlap withoutcausing the cutting discs 250 to strike each other.

One way of providing the offset of the cutters 254 may be to mount thecutters to opposite sides of the cutter support beam 260 when the cuttersupport beam 260 is embodied as a straight bar. However, in somealternative embodiments, the cutters 254 may each be affixed to the sameside of the cutter support beam 260 (e.g., the rear side, as shown inFIG. 5), but the cutter support beam 260 may be formed to have a zig zagshape as it extends transversely from one side of the cutting deck 110to the other. For example, as shown in FIG. 5, the cutter support beam260 may include parallel portions that extend substantially parallel tothe front member 200 and the rear member 230 of the frame 114. Theparallel portions may be joined together by angled portions that extendbetween each consecutive parallel portion. Each parallel portion mayhave one of the cutters 254 mounted thereto. Meanwhile, every otherparallel portion may lie in a same plane, while consecutive parallelportions are in different planes. Accordingly, since all of the cutters254 are mounted on the same side of the cutter support beam 260, thecutters 254 may all be relatively interchangeable.

In an example embodiment, the cutter support beam 260 may be supportedat each of its respective ends by a parallelogram 270. Theparallelograms 270 may extend rearward from the front member 200 suchthat the cutter support beam 260 and all of the cutters 254 fit withinthe footprint of the region defined by the frame 114. The parallelograms270 may extend substantially parallel to the first and second sidemembers 210 and 220 and therefore also substantially perpendicular tothe front member 200. The parallelograms 270 may be spaced apart fromeach other by a distance that is substantially the same as the length ofthe cutter support beam 260 so that the cutter support beam 260 may besupported proximate to its ends by the parallelograms 270. In an exampleembodiment, the parallelograms 270 may extend from the front member 200to define an angle relative to a plane in which the frame 114 lies. Themagnitude of the angle may define the height of the cutting discs 250.As such, the parallelograms 270 may function to support the cutters 254(e.g., the cutting motors 252 and the cutting discs 250) via support ofthe cutter support beam 260 and may also function to absorb or otherwisedampen mechanical shocks.

In an example embodiment, the cutter support beam 260 may not bedirectly mounted to the parallelograms 270. Instead, the cutter supportbeam 260 may have a shelf 272 disposed proximate to each end thereof andeach shelf 272 may connect to the parallelogram 270. Each shelf 272 maybe a bracket that is affixed to the cutter support beam 260 at orproximate to an end thereof to provide an adaptable attachment to theparallelogram 270 on its respective side of the cutting deck 110. Insome embodiments, each shelf 272 may be configured to allow a relativelysmall amount of upward movement of the cutter support beam 260 so that,for example, the cutter support beam 260 may move upward in response torunning into an obstacle in order to protect the cutting disc 250.

In an example embodiment, the connection of each shelf 272 to itsrespective parallelogram 270 may further enable a height of the cutters254 to be adjusted via a single operator. In this regard, for example,the angle formed between the parallelograms 270 and the plane of theframe 114 may be adjustable. Alternatively, a height of each shelf 272may be adjustable. In this regard, for example, each shelf 272 may bemounted on a separate axle. By turning the axle, e.g., via a singleheight adjuster 280, the height of the cutter support beam 260 may beadjusted. The height adjuster 280 may be positioned proximate to (orbelow) the bar extension 240 and/or the middle of the front member 200.The height adjuster 280 may be operably coupled to the axle of eachshelf 272 via connecting linkages (not shown). In an example embodiment,each shelf 272 may be configured to provide firm support for the frame114, but allow at least some motion in an upward direction to beaccommodated so that upward motion is allowable to support tolerance forbumps, collisions or rough terrain.

In some embodiments, the height adjuster 280 may be manually operable bythe operator. For example, a manual operator may be operably coupled tothe height adjuster 280 and may protrude through the cover 112.Alternatively, the operator may interact with the height adjuster 280when the cutting deck 110 is tipped as shown in FIG. 4. As yet anotheralternative, the height adjuster 280 may be operably coupled to a heightadjustment motor that may be disposed either in the working module 50 orin the power module 60 and the height adjustment motor may be operatedto adjust the cutting height of the robotic vehicle 10. The operation ofthe height adjustment motor may be conducted via the user interface 72,responsive to remote or local programming, or via any other suitablemechanism.

In some embodiments, the construction of the frame 114 and theattachments of the frame 114 to the universal support frame 100 and thecutter support beam 260 may be arranged to allow the cutting deck 110 tohave multiple degrees of freedom of motion in order to give the cuttingdeck 110 good ground tracking without requiring a large number ofvulnerable joints or complicated structures. In this regard, in someembodiments, the cutting deck 110 may have multi-axis directionalfreedom by virtue of having motion at least partially controllable inmultiple directions. For example, the X-axis may be defined as the axisof the wheels 68. Thus, X-direction motion may be controlled by thewheels 68 themselves in combination with a number of sensors (e.g., liftand collision sensors). The Y-axis may be the vertical axis (i.e., anaxis that is substantially perpendicular to the ground plane. Motionaround the Y-axis may be at least partially accounted for by virtue ofthe vertical motion of the cutters 254 that is accommodated by theparallelograms 270. The Z-axis may be an axis that extends parallel tothe ground plan and in the direction of forward motion of the roboticvehicle. Motion around the Z-axis may be permitted at least in part bythe attachment joint 120. In this regard, for example, as shown in FIG.6, the attachment joint 120 may include two rotational axes provided bya deck tilt joint 124 that enables the cutting deck to be tilted (e.g.,for cleaning or maintenance) as shown in FIG. 4, and a Z-flex joint 126that may enable movement about the Z-axis when rough terrain isencountered. Thus, for example, the Z-flex joint 126 and the deck tiltjoint 124 may be hinged about axes that are substantially perpendicularto each other.

The frame 114 may therefore be structured to provide relatively goodground coverage, while avoiding scalping of grass or hanging up on bumpsor other discontinuities in the ground being driven over. The wheelsattached to the frame and the multi-axis motion permitted byconstruction of the frame 114 may therefore enable the robotic mower 10to provide a flexible, yet consistent cutting experience whileprotecting the cutting discs 250. In some embodiments, each cutting disc250 may further be provided with a puck or some other protective featurebelow each cutting disc 250. The inclusion of the Z-flex joint 126(providing flexible rotation about the Z-axis) in combination with theparallelograms 270 (supporting the cutter support beam 260 at each endthereof) to provide both Y motion and Z-flex, and in combination withthe unique aspects of the cutting deck assembly (e.g., the protectivefeatures and wheel position) allows for a very close ground followingfeature without scalping the ground.

It should be appreciated that although the frame 114 described hereinwas specifically mentioned as a frame for a cutting deck, it is alsopossible to implement many of the structural features of the frame 114in connection with other working modules that may be employed on therobotic vehicle 10. Thus, the concepts and structures described inassociation with the frame 114 herein should not be limited toapplication with working modules that are mowers or include cuttingblades.

The control circuitry 12 of an example embodiment may include processingcircuitry that may include one or more processors and one or more memorydevices that store information for execution by the one or moreprocessors and/or information gathered by sensors of the robotic vehicle10. The control circuitry 12 may utilize the processing circuitry tocommunicate with internal and external devices to control operation ofthe robotic vehicle 10 and/or report information regarding the operationof the robotic vehicle 10 to external devices or networks. As such, thecontrol circuitry 12 may include a device interface for enablingcommunication with devices and/or sensors (e.g., via a communicationbus) and a user interface (e.g., user interface 72) for enablingcommunication with the operator.

In an example embodiment, a robotic vehicle is provided. The roboticvehicle may include a power module and a working module. The powermodule may include a battery pack (or other power source such as anengine), control circuitry configured to execute stored instructions todirect autonomous or self-guided (e.g., without direct andcontemporaneous operator interaction) operation of the robotic vehicleon a defined area, and a drive motor for propelling the robotic vehicleresponsive to control by the control circuitry. The working module maybe configured to perform a function with respect to the defined arearesponsive to being propelled by the power module. The working modulemay be one of a plurality of interchangeable working modules that areattachable to the power module. At least one of the interchangeableworking modules may have a different function than the working module.

In some cases, the features discussed above may be modified oraugmented, or additional features may be added. Such modifications,augmentations or additions may be made alone or in any combination witheach other. For example, in some cases, the interchangeable workingmodules may each be interchangeably and separately attachable to thepower module without the use of tools. Alternatively or additionally,the interchangeable working modules may include a cutting deck, a snowthrowing attachment, a brush cutting attachment, a sweeping attachment,or a watering attachment. Alternatively or additionally, at least one ofthe interchangeable working modules may perform the same function as theworking module, but may be configured to have a different size than theworking module. Alternatively or additionally, the power module mayfurther include one or more sensors of a sensor network. In such anexample, the one or more sensors may be configured to detect objectsencountered during operation of the robotic vehicle to determine alocation of the robotic vehicle based on the objects detected, todetermine a location of the vehicle relative to boundaries of thedefined area or a point of interest associated with the defined area,and/or to detect collision, lifting, or tipping of the robotic vehicle.In some cases, each of the one or more sensors of the sensor network maybe in communication with the control circuitry via a singlecommunication bus that extends between the power module and the workingmodule. In addition or as an alternative to the features above, thepower module may include a universal frame support extending from afront portion of the power module to engage the working module. Theuniversal frame support may extend substantially parallel to a surfaceover which the power unit transits and extends over at least a portionof the working module and/or may include an attachment joint that isrotatably attachable to the working module. The attachment joint may bedisposed at a distal end of the universal support frame, and areleasable coupling may engage another portion of the universal supportframe to the working module during operation of the working module. Insome cases, the releasable coupling may be released to enable theworking module to be pivoted about the attachment joint. The attachmentjoint may be configured to enable pivoting of the working module aboutan axis that extends in a transverse direction, and the attachment jointmay further include a flexible joint configured to enable pivoting ofthe working module about an axis that extends substantiallyperpendicular to the transverse direction. In some cases, the workingmodule may include a cutting deck including a frame that is operablycoupled to a cutter support beam supporting a plurality of cuttingdiscs. In an example embodiment, the cutter support beam extendstransversely across the cutting deck and the cutting discs are mountedto opposite sides of the cutter support beam. In some cases, the cuttersupport beam extends transversely across the cutting deck and thecutting discs are mounted to the same side of the cutter support beam.In an example embodiment, the cutter support beam extends transverselyacross the cutting deck and is operably coupled to the frame by aparallelogram disposed at each opposing end of the cutter support beam.In some embodiments, an angle between the parallelogram and the frame isadjustable to adjust a height of the cutter support beam. In some cases,the parallelogram may be operably coupled to the frame via a bracket andthe parallelogram is attachable to different vertically oriented pointsof the bracket to adjust a height of the cutter support beam. In anexample embodiment, the cutting deck includes outer wheels disposedproximate to opposing transverse ends thereof, and the cutting discfurther includes at least one protective feature configured to inhibitthe cutting discs from engaging the ground. In some cases, the at leastone protective feature may include a puck disposed at a bottom portionof at least one of the cutting discs. In an example embodiment, the atleast one protective feature may include an interior wheel disposedbetween the outer wheels, the interior wheel may be configured to bespaced apart from a plane in which ground engaging portions of the outerwheels are disposed.

In another example embodiment, a robotic vehicle is provided that mayinclude a power module and a working module. The power module mayinclude a battery pack, control circuitry configured to execute storedinstructions to direct autonomous or self-guided operation of therobotic vehicle on a defined area, and a drive motor for propelling therobotic vehicle responsive to control by the control circuitry. Theworking module may have a frame and be configured to perform a functionwith respect to the defined area responsive to being propelled by thepower module. The power module may include a universal frame supportextending from a front portion of the power module to rotatably engage aportion of the frame of the working module.

In some cases, the features discussed above may be modified oraugmented, or additional features may be added. Such modifications,augmentations or additions may be made alone or in any combination witheach other. For example, in some cases, the universal frame support mayextend substantially parallel to a surface over which the power unittransits and extends over at least a portion of the working module toengage the frame. Alternatively or additionally, the universal supportframe may include an attachment joint that is rotatably attachable tothe working module. In some cases, the attachment joint may be disposedat a distal end of the universal support frame, and a releasablecoupling may engage another portion of the universal support frame tothe working module during operation of the working module. In someembodiments, the releasable coupling may be released to enable theworking module to be pivoted about the attachment joint. In an exampleembodiment, the attachment joint may be configured to enable pivoting ofthe working module about an axis that extends in a transverse directionacross the working module, and the attachment joint may further includea flexible joint configured to enable pivoting of the working moduleabout an axis that extends substantially perpendicular to the transversedirection.

In yet another example embodiment, a robotic vehicle is provided thatmay include a power module and a cutting deck. The power module mayinclude a battery pack, control circuitry configured to execute storedinstructions to direct autonomous or self-guided operation of therobotic vehicle on a defined area, and a drive motor for propelling therobotic vehicle responsive to control by the control circuitry. Thecutting deck may include a frame that is operably coupled to a cuttersupport beam supporting a plurality of cutting discs configured toperform a cutting function with respect to the defined area responsiveto being propelled by the power module. The cutting deck may bereleasably and pivotally attached to a forward portion of the powermodule.

In some cases, the features discussed above may be modified oraugmented, or additional features may be added. Such modifications,augmentations or additions may be made alone or in any combination witheach other. For example, in some cases, the power module may include auniversal frame support extending from a front portion of the powermodule to engage a portion of the frame of the cutting deck. In somecases, the cutter support beam extends transversely across the cuttingdeck and the cutting discs are mounted to opposite sides of the cuttersupport beam. In an example embodiment, the cutter support beam may besubstantially straight while extending transversely across the cuttingdeck. In some embodiments, the cutter support beam extends transverselyacross the cutting deck and the cutting discs are mounted to the sameside of the cutter support beam. In an example embodiment, the cuttersupport beam extends transversely across the cutting deck in a zigzagpattern. Additionally or alternatively, the cutter support beam mayextend transversely across the cutting deck and is operably coupled tothe frame by a parallelogram disposed at each opposing end of the cuttersupport beam. In some cases, an angle between the parallelogram and theframe may be adjustable to adjust a height of the cutter support beam.In some embodiments, the parallelogram is operably coupled to the framevia a bracket and the parallelogram is attachable to differentvertically oriented points of the bracket to adjust a height of thecutter support beam. In an example embodiment, the cutting deck mayinclude outer wheels disposed proximate to opposing transverse endsthereof, and the cutting disc may further include at least oneprotective feature configured to inhibit the cutting discs from engagingthe ground. In some cases, the at least one protective feature may be apuck disposed at a bottom portion of at least one of the cutting discs.Alternatively or additionally, the at least one protective feature maybe an interior wheel disposed between the outer wheels where theinterior wheel is configured to be spaced apart from a plane in whichground engaging portions of the outer wheels are disposed.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Moreover, although the foregoing descriptions and the associateddrawings describe exemplary embodiments in the context of certainexemplary combinations of elements and/or functions, it should beappreciated that different combinations of elements and/or functions maybe provided by alternative embodiments without departing from the scopeof the appended claims. In this regard, for example, differentcombinations of elements and/or functions than those explicitlydescribed above are also contemplated as may be set forth in some of theappended claims. In cases where advantages, benefits or solutions toproblems are described herein, it should be appreciated that suchadvantages, benefits and/or solutions may be applicable to some exampleembodiments, but not necessarily all example embodiments. Thus, anyadvantages, benefits or solutions described herein should not be thoughtof as being critical, required or essential to all embodiments or tothat which is claimed herein. Although specific terms are employedherein, they are used in a generic and descriptive sense only and notfor purposes of limitation.

That which is claimed:
 1. A robotic vehicle comprising: a power moduleincluding: control circuitry configured to execute stored instructionsto direct operation of the robotic vehicle on a defined area; and adrive motor for propelling the robotic vehicle responsive to control bythe control circuitry; and a working module configured to perform afunction with respect to the defined area responsive to being propelledby the power module, wherein the working module is one of a plurality ofinterchangeable working modules that are attachable to the power module,wherein at least one of the interchangeable working modules has adifferent function than the working module, wherein the power moduleincludes a universal frame support extending from a portion of the powermodule to engage the working module, and wherein the universal supportframe includes an attachment joint that is rotatably attachable to theworking module, and wherein the attachment joint is disposed at a distalend of the universal support frame, and wherein a releasable couplingengages another portion of the universal support frame to the workingmodule during operation of the working module, and wherein thereleasable coupling is released to enable the working module to bepivoted about the attachment joint.
 2. The robotic vehicle of claim 1,wherein the interchangeable working modules are each interchangeably andseparately attachable to the power module without the use of tools. 3.The robotic vehicle of claim 1, wherein the interchangeable workingmodules include a cutting deck, a snow throwing attachment, a brushcutting attachment, a sweeping attachment, or a watering attachment. 4.The robotic vehicle of claim 1, wherein at least one of theinterchangeable working modules performs the same function as theworking module, but is configured to have a different size than theworking module.
 5. The robotic vehicle of claim 1, wherein the powermodule further includes one or more sensors of a sensor network, andwherein the one or more sensors are configured to detect objectsencountered during operation of the robotic vehicle to determine alocation of the robotic vehicle based on the objects detected.
 6. Therobotic vehicle of claim 1, wherein the power module further includesone or more sensors of a sensor network, and wherein the one or moresensors are configured to determine a location of the vehicle relativeto boundaries of the defined area or a point of interest associated withthe defined area.
 7. The robotic vehicle of claim 1, wherein the powermodule further includes one or more sensors of a sensor network, andwherein the one or more sensors are configured to detect collision,lifting, or tipping of the robotic vehicle.
 8. The robotic vehicle ofclaim 1, wherein the power module further includes one or more sensorsof a sensor network, and wherein each of the one or more sensors of thesensor network is in communication with the control circuitry via asingle communication bus that extends between the power module and theworking module.
 9. The robotic vehicle of claim 1, wherein the universalframe support extends substantially parallel to a surface over which thepower unit transits and extends over at least a portion of the workingmodule.
 10. The robotic vehicle of claim 1, wherein the attachment jointis configured to enable pivoting of the working module about an axisthat extends in a transverse direction, and wherein the attachment jointfurther includes a flexible joint configured to enable pivoting of theworking module about an axis that extends substantially perpendicular tothe transverse direction.
 11. The robotic vehicle of claim 1, whereinthe working module comprises a cutting deck including a frame that isoperably coupled to a cutter support beam supporting a plurality ofcutting discs, and wherein the cutter support beam extends transverselyacross the cutting deck and the cutting discs are mounted to oppositesides of the cutter support beam.
 12. The robotic vehicle of claim 1,wherein the working module comprises a cutting deck including a framethat is operably coupled to a cutter support beam supporting a pluralityof cutting discs, wherein the cutter support beam extends transverselyacross the cutting deck and is operably coupled to the frame by aparallelogram disposed at each opposing end of the cutter support beam,and wherein an angle between the parallelogram and the frame isadjustable to adjust a height of the cutter support beam.
 13. Therobotic vehicle of claim 1, wherein the working module comprises acutting deck including a frame that is operably coupled to a cuttersupport beam supporting a plurality of cutting discs, wherein the cuttersupport beam extends transversely across the cutting deck and isoperably coupled to the frame by a parallelogram disposed at eachopposing end of the cutter support beam, and wherein the parallelogramis operably coupled to the frame via a bracket and the parallelogram isattachable to different vertically oriented points of the bracket toadjust a height of the cutter support beam.
 14. The robotic vehicle ofclaim 1, wherein the working module includes outer wheels disposedproximate to opposing transverse ends thereof, and wherein the workingmodule further includes at least one protective feature configured toinhibit an operating tool of the working module from engaging theground, and wherein the at least one protective feature comprises a puckdisposed at a bottom portion of the operating tool.
 15. The roboticvehicle of claim 1, wherein the working module includes outer wheelsdisposed proximate to opposing transverse ends thereof, and wherein theworking module further includes at least one protective featureconfigured to inhibit an operating tool of the working module fromengaging the ground, and wherein the at least one protective featurecomprises an interior wheel disposed between the outer wheels, theinterior wheel being configured to be spaced apart from a plane in whichground engaging portions of the outer wheels are disposed.
 16. A roboticvehicle comprising: a power module including: control circuitryconfigured to execute stored instructions to direct operation of therobotic vehicle on a defined area; and a drive motor for propelling therobotic vehicle responsive to control by the control circuitry; and aworking module having a frame and configured to perform a function withrespect to the defined area responsive to being propelled by the powermodule, wherein the power module includes a universal frame supportextending from a front portion of the power module to rotatably engage aportion of the frame of the working module, wherein the universalsupport frame includes an attachment joint that is rotatably attachableto the working module, and wherein the attachment joint is disposed at adistal end of the universal support frame, and wherein a releasablecoupling engages another portion of the universal support frame to theworking module during operation of the working module, and wherein thereleasable coupling is released to enable the working module to bepivoted about the attachment joint.
 17. A robotic vehicle comprising: apower module including: control circuitry configured to execute storedinstructions to direct operation of the robotic vehicle on a definedarea; and a drive motor for propelling the robotic vehicle responsive tocontrol by the control circuitry; and a deck including a frame that isoperably coupled to a support beam supporting a plurality of operationaltools configured to perform a function with respect to the defined arearesponsive to being propelled by the power module, wherein the powermodule includes a universal frame support extending from a portion ofthe power module to the deck, and wherein the universal su ort frameincludes an attachment joint that is rotatably attachable to the deck,and wherein the attachment joint is disposed at a distal end of theuniversal support frame, and wherein a releasable coupling engagesanother portion of the universal support frame to the deck duringoperation of the deck, and wherein the releasable coupling is releasedto enable the deck to be pivoted about the attachment joint.